protected void UpdateTargetProperty(IList <MediaItem> items, MediaItemQueryMode queryMode)
{
IDataDescriptor targetDataDescriptor = _targetDataDescriptor;
if (targetDataDescriptor == null)
{
return;
}
object result;
//Try and update our target property with either a media item enumeration or the first media item
if ((queryMode != MediaItemQueryMode.SingleItem && TypeConverter.Convert(items, targetDataDescriptor.DataType, out result)) ||
(queryMode != MediaItemQueryMode.MultipleItems && TypeConverter.Convert(items != null ? items.FirstOrDefault() : null, targetDataDescriptor.DataType, out result)))
{
lock (_syncObj)
{
//Avoid multiple updates with the same value
if (ReferenceEquals(_lastUpdatedValue, result))
{
return;
}
_lastUpdatedValue = result;
}
targetDataDescriptor.Value = result;
}
}
//Performs the actual query and updates the target property with the returned media item(s)
protected void QueryMediaItems()
{
IFilter filter = Filter;
if (filter == null)
{
//Set target property to null if invalid to remove any previously assigned media items
UpdateTargetProperty(null, QueryMode);
return;
}
IContentDirectory cd = ServiceRegistration.Get <IServerConnectionManager>().ContentDirectory;
if (cd == null)
{
return;
}
MediaItemQueryMode queryMode = QueryMode;
MediaItemQuery query = new MediaItemQuery(NecessaryRequestedMIAs, OptionalRequestedMIAs, filter);
if (queryMode == MediaItemQueryMode.SingleItem)
{
query.Limit = 1;
}
IList <MediaItem> items = cd.Search(query, true, GetCurrentUserId(), false);
UpdateTargetProperty(items, queryMode);
}
